In diagnosing and treating diseases of various body cavities and organs, it is necessary to deliver various medical instruments to the organs and tissue sites at specified locations.
In the field of drug delivery, many therapeutic and/or diagnostic agents may not be delivered via traditional drug delivery routes, such as non-invasive peroral, topical, transmucosal or inhalation routes. This is because such therapeutic/diagnostic agents are susceptible to enzymatic degradation or cannot be absorbed into the systemic circulation efficiently due to molecular size and charge issues, and thus, will not be therapeutically effective if delivered via the above mentioned routes.
Often, it is also necessary to deliver medicinal or therapeutic substances to remote and not easily accessible blood vessels and other lumens within body organs, such as lungs. It is also important to be able to deliver defined doses of cytotoxic therapeutic and diagnostic substances directly into target tissue because such substances are often very expensive or are capable of causing serious harm if delivered in excess. Therefore, there is a need for systems and methods capable of delivering therapeutic and diagnostic agents directly to target tissue sites inside a patient's body.
It is also desirable to be able to introduce various medical instruments and devices to targeted tissues to assist in performing drug therapy or related therapeutic or diagnostic procedures, such as biopsy, radio therapy, incisions, laser treatment, etc. Such devices often have to be inserted into and guided through remote and not easily accessible bodily lumens, and then positioned precisely to be able to perform a desired medical procedure.
Several devices have been proposed for a targeted delivery of drugs to internal bodily cavities. For example, U.S. Pat. No. 6,283,947 to Mirzaee discloses a catheter for injecting medication to a specific location within a patient's artery. The catheter includes two drug delivery needles positioned at opposite ends of the catheter shaft and may also include an inflatable balloon positioned between the needles for pushing the needles outwardly upon inflation.
U.S. Pat. No. 6,692,466 to Chow et al. discloses a drug delivery catheter having a balloon disposed at its distal end and a drug delivery assembly, e.g. as needle, disposed in a delivery lumen attached to the balloon wall. During use, the catheter is inserted into a patient's body, the balloon is inflated and the needle is extended out of the delivery lumen on the side of the balloon.
There are also a number of systems designed to introduce various medical devices into bodily lumens. U.S. Pat. No. 7,182,756 to Saeed et al. discloses a device for directing a wire guide including an inflatable balloon or an expandable wire basket positioned at a distal end of a catheter shaft, and a guide wire extended out of an opening in the shaft proximal of the balloon. When the balloon or basket is expanded, it comes into contact with the guide wire and is capable of deflecting it.
U.S. patent application No. 2012/0053485 to Bloom discloses a catheter having a biopsy needle and one or more expandable support members coupled to the outer surface of a catheter shaft for anchoring the catheter within a bodily cavity. The needle and the catheter shaft with the balloon may be positioned side by side inside an outer sheath and extended out of the outer sheath once inserted into a patient's body. The needle extends at a non-zero degree angle which may be varied by expansion of the balloon.
While the above described systems are useful for delivering the drugs and related medical instruments/devices to a specific location within a patient's body, these systems still suffer from a number of disadvantages and drawbacks. One of the major problems with the prior art systems described above is that is that they are rather bulky and complex in structure, which makes them unsuitable for use in bodily cavities having a very small diameter, such as lungs. Additionally, these known systems are typically constructed with expensive materials and require multiple working components, and therefore have to be reused multiple times, which requires complex sterilization procedures.
Another problem is that the structure of the devices described above does not allow for optimally safe insertion and operation of the devices in a patient's body. In particular, in the devices discussed above, sharp portions of drug delivery needles or other medical devices are either exposed to surrounding tissue during the insertion or retraction of the device, or become abruptly exposed to surrounding tissue once a protective sheath is removed. This increases chances of harmful injury to surrounding bodily cavities and tissues during operation of the devices. Furthermore, the known devices do not provide a safety mechanism to prevent the drug delivery needles or other sharp instruments from accidently puncturing the inflatable balloon during the procedure.
A further deficiency of the prior art systems described above is that they are not capable of being positioned as optimally and precisely as may be desired. The known devices do not provide illumination and a direct visual feedback of the area ahead, behind, and around the device to optimize positioning and operation of the device.
Yet another shortcoming of the known systems is that they lack the capability to precisely gauge the size of the environment in which they are being used to provide physiological measurements and feedback that could aid precise and secure positioning and operation of the device. For example, the prior art devices do not enable the surgeon to measure the intra-lumen dimensions of the bodily cavity in which the device is to be operated, and provide no way to accurately adjust for changes in these dimensions during the procedure. Furthermore, the known devices are not capable of accounting for one or more vital signs and physiological parameters of the patient facilitate more precise positioning of the desired medical device/instrument relative to target tissue site.
What is desired, therefore, is an improved system and method for delivering various medical instruments and devices to specific locations inside a patient's body that address the disadvantages and shortcoming of the prior art systems described above.